Non blooming Shasta Daisies

Tall, healthy shastas but no blooms. 3 different locations in yard, leaves look great, a tight whorl on top where the flower should form of a lighter green. All the plants receive lots of sun with a little shade from other plants at different times of the day. I have added phosphate to encourage blooms to no avail.

Other than having an abundance of nitrogen in the soil, which is normally offset with phosphorus, I really don't know what else would be keeping the plants from blooming. You may need to get a soil test to see exactly what, if anything, needs to be corrected as far as nutrients go, but the addition of bone meal shouldn't hurt.